


Changing Tides

by liddie



Series: The Hobbit AU Series [5]
Category: The Hobbit (Jackson Movies), The Hobbit - All Media Types
Genre: Adorable parents!Fíli & Kíli, Alternate Universe - Fantasy, Explicit Sexual Content, Fluff, Hurt/Comfort, Interspecies Relationship(s), Interspecies Sex, M/M, Mer!AU, Mermaids, Mpreg, Romance, There will be a baby
Language: English
Status: In-Progress
Published: 2013-10-31
Updated: 2013-12-15
Packaged: 2017-12-31 00:40:47
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 5
Words: 15,677
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1025300
Author URL: https://archiveofourown.org/users/liddie/pseuds/liddie
Summary: <blockquote class="userstuff">
              <p>After a late night encounter with his favorite brunet human, Fíli finds himself in a situation he never thought possible.</p><p>aka Fíli and Kíli are in for a surprise as they figure out what comes next--parenting!</p>
            </blockquote>





	1. Prelude to Baby

**Notes for the Chapter:**

> *sucks in deep breath* 
> 
> Here is the spin-off of Playful Waves, where our happy couple takes a(n unexpected) step forward in their relationship. I figure they're about 19-20ish here.
> 
> This will be an mpreg story...I REPEAT-THERE WILL BE MPREG. If you don't like that sort of thing, I wouldn't advise you read on after this chapter.

* * *

The full moon hangs in the night sky, a cool breeze flitting across the sand and stirring up gull feathers across the beach. The waves lap at the sandy shore, pushing and pulling the sand in soothing, rhythmic motions. A soft melody floats across water and sand, rising and falling with the breeze as it wraps around the lone figure walking down the dark beach.

Kíli stumbles through the sand on autopilot, his mind a cloudy haze and eyes glazed over as he follows the eerie song down to the water. He stumbles past the old dock and pauses, glassy eyes focusing on the figure lying seductively across the surf. When the figure crooks a finger at him, Kíli stumbles forward and into the dark waters.

Fisting cool hands in his t-shirt, the mer drags Kíli out into deeper waters, sand disappearing beneath the brunet’s feet as he sinks below the surface. With a tug on his shirt, he pops back up, smiling drunkenly at the sharp teeth that flash in a dark smile before he’s pulled forward into a searing kiss.

As his head starts to clear, Kíli’s eyes blink open and the haze drifts away. His senses come back to him in a rush, limbs flailing when he realizes where he is. Pushing the figure back with a shout, Kíli topples backwards into the water and tries to find his bearings.

He surfaces with a deep intake of breath, coughing and swimming a few feet back to shore. The figure circles below, though Kíli doesn’t take notice as he coughs up seawater onto the beach.

“Wha? How did I…” Whipping his head around, Kíli’s wide eyes search the dark water as his hand comes up to touch his lips lightly. They still tingle from the pressure of the kiss, Kíli shifting to sit on his bottom as he watches a dark figure swim closer. Bringing his legs up to his chest, Kíli waits with wary eyes as the mer surfaces.

“Fíli,” Kíli breathes in relief, legs relaxing as he falls over to his side in the wet sand. The blond keeps his dark eyes trained on the human as he advances, frowning and staying back as Kíli lies on his side with eyes closed.

“You scared the crap out of me,” Kíli’s voice cuts through the silence, a grin spreading across Fíli’s face as he drags himself up next to the brunet.

“Missed you,” Fíli says lowly, something deep churning in his voice. Kíli cracks an eye open, rolling onto his back and giving the blond an unimpressed look.

“Missed me? You just saw me a few hours ago!”

“Missed you, want you,” Fíli purrs, hefting himself up to drape over Kíli, bottom half settling not-so-subtly over Kíli’s crotch. His tail smacks at the water, bending up behind the blond to hover in the air, fins dripping water over both Fíli’s shoulder and Kíli’s stomach.

Kíli shakes his head with a fond smile, bringing sandy hands up to run through thick blond hair. “You called me down here in the middle of the night because you _missed_ me?” The brunet asks, shifting his legs and spreading them so Fíli’s bottom half lines up with his own. The blond lets out a whine, rubbing himself against Kíli and digging his hands into the sand at their sides. “You only want me for my body.”

“Kiliiii,” Fíli moans, tail falling down to slap at the water. Kíli bucks up into the blond’s hips in experiment, Fíli grinding back down into him instantly.

“Someone’s needy tonight,” Kíli comments with a laugh, pushing at Fíli’s shoulders so he can sit up. The blond’s pout turns hopeful when Kíli strips his wet shirt off, throwing it blindly up onto the beach. Fíli nods distractedly, fingers clawing at the drawstrings on Kíli’s shorts. When he can’t undo the knot, Fíli huffs and slashes through the strings with sharp nails, giving the brunet an unapologetic look as he tugs at the fabric.

Lifting his hips, Kíli laughs as Fíli wiggles the shorts halfway down his thighs, another frustrated whine cutting through the night when the wet fabric clings to skin. Eyes darting up to Kíli, the brunet furrows his brow in confusion right before he realizes what Fíli’s about to do.

Before he can protest, Fíli’s hands are under his shorts and against his thighs, turning outward and slicing the fabric clean down the sides. With a satisfied grin, Fíli pulls the torn cloth from Kíli’s legs and throws it behind the brunet’s head.

“Fíli! Did you really have to—oh!”

Fíli takes the flushed erection into his mouth, suckling and swirling his tongue around the head with wet noises. Kíli throws his head back with a groan, hands coming up to fist in the merman’s hair. The blond relaxes his throat, taking more of Kíli down as he hums around the mouthful.

“Oh shit, Fee, you’re so good,” Kíli moans, fingers scratching at the blond’s scalp as he begins to bob his head. Kíli squeezes his eyes shut at the warmth around his cock, letting out a shaky breath as he directs dark eyes down to the blond.

Fíli’s looking up at him with black eyes, his bottom half shifting in the sand with small rocking motions. Kíli lets out a grunt and pulls at blond hair, Fíli leaning up and off of him with a wet pop. Leaning up onto his arms, Kíli can see Fíli’s erection jutting into the sand.

“C’mon, back up,” Kíli murmurs, following Fíli’s slide down and into the water. When he’s sitting waist deep, reaches over to pull the merman into a kiss, his hand sneaking down to wrap around Fíli’s thick arousal.

Moaning into the kiss, Fíli brings his arms up and around Kíli’s neck, dropping his head onto the brunet’s shoulder and thrusting his hips into Kíli’s hand. “Kíli puhleasse, fuck, Kíli!”

Tightening his grip around Fíli, Kíli leans his head back and looks down at the blond. “What’s gotten into you tonight?” He murmurs, Fíli panting against him and shaking his head into his shoulder. Kíli reaches his free hand back to find Fíli’s crease, dipping a finger inside the blond and marveling at how wet he is inside. Fíli leans up to bite Kíli’s shoulder softly, trying not to draw blood as the human fucks him with a finger.

“More, want Kíli. Fuck me, puhleasse,” the merman moans when Kíli adds another digit, the blond’s natural slick allowing the fingers to slip in easily. Kíli twists his fingers on an inward thrust, Fíli letting out a shriek that’s partially muffled as he bites down into Kíli’s shoulder.

“Fuck!’ The brunet hisses, the sting of the bite quickly fading as Fíli laps at the punctures with apologetic licks. He sucks over the wound, creating a dark bruise across tanned skin. Kíli scissors his fingers, stretching Fíli open and pumping at his cock in a steady rhythm.

“Sorry, Kee, sorry,” Fíli mumbles around a string of moans and garbled words, lifting his head and locking eyes with the brunet. Leaning forward clumsily, Fíli smashes his lips against the human’s, Kíli’s hands darting from Fíli to steady himself in the soft sand.

Fíli uses the distraction to shift and wiggle around into Kíli’s lap, sitting sideways and lining himself up to sink down Kíli’s erection in a single swift movement.

“FÍLI!” The brunet shouts, his hands shooting up to wrap around Fíli’s waist and hold him still. Fíli keens at the full feeling inside, one arm coming up to loop around Kíli’s neck while he uses the other to balance on Kíli’s knee.

A tear leaks out of Fíli’s eye, and when the blond tries to rock in Kíli’s lap, the brunet tightens his arms and holds the merman still. “Stop, Fee. I’m not going anywhere.” Kíli bites out into Fíli’s ear, the tight sheathe of the blond’s insides squeezing around him like a vice.

Fíli slumps against him, hand burying in Kíli’s hair as he nuzzles into the brunet’s neck. His free hand moves from Kíli’s knee up his thigh in a petting motion, long legs relaxing under the motions.

“If you’ve hurt yourself, we’re stopping this instant,” Kíli mutters, rubbing a hand along Fíli’s hips and tail to try and relax the blond. Fíli coos against him, hips moving in subtle circles around Kíli’s erection.

“Love you,” Fíli whispers against Kíli’s neck, leaning back to place a kiss to the corner of the human’s mouth. Kíli turns into the kiss, hips jerking up unconsciously to bury himself deeper in the tight warmth.

Fíli leans back with a moan, his tail coming to curl up and around Kíli's backside and squeeze him close. Lifting himself experimentally, Fíli rocks back down onto the stiff length with a breathy sigh.

Kíli watches Fíli’s face in the moonlight, searching for any sign of pain or discomfort. As he continues to rock up and down, all Kíli can see is pleasure and heat building up in the blond’s eyes. With a smile of relief, Kíli shifts his hips up into Fíli’s downward thrusts, his hand creeping over the merman’s waist to wrap around his erection once more.

“Kee, yes! Harder!” Fíli moans brokenly, the flat of his tail fin coming up to press against Kíli’s back as he picks up his pace. Kíli thrusts his hips, bouncing Fíli up and into the tight grip of his hand with a moan.

“So good, Fíli, so tight for me,” Kíli mumbles around moans of his own, tightening his hand around the blond’s cock and feeling Fíli’s insides clench in response. The water splashes around them, Kíli shivering from its chill and the tight, silky feeling of Fíli’s insides around him.

Fíli comes with a garble of strange words, his release spurting into Kíli’s hand and dribbling down into the water. Kíli picks up his pace, thrusting into the unyielding clenching and shouting out when he tips over the edge.

Fíli’s tail presses against his back, the blond’s hips moving from side to side as Kíli releases into him with a strangled moan. Fíli lets out a low whine and continues to rock Kíli through his orgasm, grinding down and clenching around both the cock and cum inside him. He leans heavily against the brunet, whining when Kíli tries to shift him out of his lap.

“Stay, Kee stay inside,” Fíli murmurs, looping both arms around Kíli’s neck and burying his face in the brunet’s neck. Bringing an arm up to wrap around the merman’s waist, Kíli hugs the blond and presses a kiss to his damp hair.

They sit in the water for a while longer, though Kíli’s shivering has the blond carefully leaning up and off of Kíli’s spent cock. The brunet groans as he slips free, Fíli shifting away and ducking under the water for a few seconds. Kíli crawls through the water towards the beach, collapsing on the sand with a yawn. Fíli comes up behind him with the bag of clothes from under the dock, throwing it onto the beach and chuckling when Kíli wades into the water to try and rinse the sand off.

“A little help, please?”

Splashing the human with his tail, Fíli thoroughly showers the brunet and grins appreciatively when Kíli leans over to grab the bag of clothes. Using the shirt to dry himself off, Kíli slips the shorts on, throwing the shirt at a grinning Fíli and laughing when it covers the blond’s head.

Wading back out up to his knees, Kíli leans down to meet Fíli halfway in a kiss. The blond runs his hand along Kíli’s cheek in an affectionate gesture, tilting his head to the side and deepening the kiss. Pulling back with a sigh, Kíli cups Fíli’s face and nuzzles their noses together in a spur of the moment gesture. “Love you.”

He pulls back with a laugh, releasing the blond and walking back up to the shore. Kíli plops down in the sand and lays back, making sure to be within reach of the water. He’s already awake, so if Fíli wants to continue being affectionate, he won’t stop him. Fíli will have to come to him though, the thought of staying in the cool water giving Kíli the chills.

Sure enough, a few minutes later and Fíli is dragging himself up the beach, the lower half of his dark tail flicking in the water a few feet below. He shifts onto his side, head pillowed on Kíli’s chest as a hand traces words on the brunet’s stomach.

“Fee, why did you call me here? I thought you didn't like to use the song,” Kíli asks quietly, running his hand up and down Fíli’s arm as he waits for an answer. The merman shrugs against him, soft words spoken against tanned skin.

“Missed Kíli. Warmth, need…happy. Together.” Fíli tries to explain so Kíli will understand, but truth be told, he’s not really sure himself. He breathes easier around the brunet, and for some reason he had needed to just be around the human tonight.

Kíli stays quiet, wrinkling his nose and sneezing loudly into his arm. Shaking his head, Kíli yawns and brings his free arm up behind his head. Fíli snuggles against him with a content sigh, warm breath fanning over his chest as the blond drifts to sleep. 

* * *

 

**Notes for the Chapter:**

> *exhales loudly*
> 
> This probably won't be updated as often as I'd like, I find myself in the drabble mood a lot lately. I feel bad posting anything less than 1500 words on Ao3 for some reason. I do have some notes for different chapters of this story, but I have to wade through them and figure out what I want to turn into chapters.
> 
> Let me know what you think! I know it isn't much (but sex) right now, but I do have a huge chunk of the story written and waiting to be posted.


	2. Ut oh...

**Summary for the Chapter:**

> Fíli tries to figure out his sudden weight gain and Balin lays everything out on the table. The next few steps are going to be the hardest...telling everyone the news.

**Notes for the Chapter:**

> Ugh, I've been looking at this all day and now I'm sick of it. 
> 
> I apologize for any mistakes and such, I changed a few things from the original oneshot. I might edit this more tomorrow but who knows.
> 
> Thank you for the amazing responses ~ I love reading each and every comment, they make my day!

 

* * *

Water shifts through the sunken ship in a slight current, bringing with it a gathering of small fish and drifting particles. A blond merman sits against the sleek wooden planks, fin bent underneath him as he furrows a brow in thought.

Fíli stares down at his normally flat stomach, running a hand over the small bump that has started to form. He tries to think back on any different eating habits he might have picked up, though as much as he wracks his brain, he comes up empty every time.

Fíli can’t figure out how he’s gotten the small bump; he gets a lot of exercise swimming up to see Kíli each day, so his levels of physical activity haven’t changed. If anything, they’ve increased due to the new steps he and Kíli had taken with their relationship.

A few weeks ago he had gotten ill, though Thorin had dismissed it as some kind of food sickness from the new fish they’d caught. After a few days of the sickness, Fili felt fine and even started eating more than usual, though everyone knew this was common for mermen who were still growing into maturity.

Rubbing his stomach softly, the blond leans back against the ship’s hull and watches the colorful fish dart around. He is utterly bored, Kíli having left on a trip into a larger city for supplies with his mother. The brunet had estimated their time apart at about a week, and though it’s been only a few days, Fíli misses the brunet human who’s become a solid constant in his life.

With a sigh, Fíli stretches out his tail and makes to leave, stopping when Dwalin appears in the cracked side of the ship. The warrior gives him an annoyed look, Fíli answering with a smug grin, pleased he’s hidden from the warrior and his uncle this long.

“There you are, Thorin’s been—”

Dwalin cuts himself off abruptly, his wide eyes focusing in on Fíli’s stomach. The blond gives him a worried look, swimming closer and resting his arm on Dwalin’s shoulder.

“Dwalin, what’s wrong? Is everything okay with Uncle?”

“What’s that?” The warrior asks gruffly, Fíli glancing down at his stomach with a frown. His free hand comes up to press against the bump, an embarrassed flush spreading over his cheeks when he realizes the extra weight is more noticeable than he thought.

“It’s nothing, I just haven’t been swimming as much a normal,” Fíli said with a wave of his hand, Dwalin’s hand snapping out to catch the blond’s wrist in a tight hold as he leans down to inspect the bulge. Fíli watches him with a confused look, and when Dwalin moves his hand up to hover over Fíli’s stomach, he stops himself and looks up for permission.

With a confused nod from the blond, Dwalin splays his hand across the smooth skin of Fíli’s stomach, fingers probing the skin and massaging it lightly. Fíli’s frown flattens out, though he still has no idea why his weight gain has the warrior so upset.

“That’s not just added weight,” Dwalin whispers, pulling his hand back and giving Fíli a worried look. “You uncle is going to kill him.”

“Dwalin, what are you talking about? It’s no ones fault but my own for this weight, I’m sure I can lose it easily enough,” Fíli says with confidence, though the look on Dwalin’s face has the smile quickly slipping off his face. “W-what’s going on? Am I sick?”

Shaking his head at the blond’s questions, Dwalin motions for the prince to follow him, swimming around the back way through the nest. They enter Balin’s study, the white haired merman looking up and smiling at the sight of them. His grin slips as he takes in the look on his brother’s face, Dwalin checking outside to make sure they’re alone before ushering Fíli through a doorway into a private cavern.

“Brother, what’s all this?” Balin asks, sharing a confused look with the blond prince. Fíli’s face has paled, his head filling with different scenarios to explain why Dwalin is acting the way he is. Dwalin motions to Fíli’s stomach, Balin swimming a bit closer to take a better look.

“Tell me it isn’t what I think it is,” Dwalin demands, Fíli’s hands coming up to cover the bump from view. Balin lays a gentle hand over Fíli’s, pushing it down and away from the once flat stomach.

“It’s nothing, Master Balin.” Fíli insists, though the sharp intake of breath from the elder has Fíli’s worry escalating.

“Does Thorin know?”

“Of course not! Do you think I have a death wish?” Dwalin snaps, shaking his head and apologizing softly to his brother. “Fíli doesn't even know.”

“I don't know what? That I’ve gained a bit of weight? Of course I know, and I told you I’ll have it gone in—”

“Three months,” Balin finishes, leaning back up and looking Fíli seriously in the eyes. The prince furrows his brows, about to argue back until Balin cuts him off again.

“Anything sooner will be a risk for you both,” Balin says, swimming over to a ledge in the wall, filled with stacks of shale writings. He digs through them noisily, Dwalin urging Fíli over to a nearby rock to sit.

“I don’t understand,” Fíli starts, staring down at this stomach as he twists his hands, sharp claws catching on soft palms.

“Where is Kíli? Are you meeting him today?” Dwalin asks suddenly, Fíli’s head shooting up and giving the warrior a negative shake.

“He’s gone for a week, traveling to a larger city with his mother.” Dwalin’s sigh of relief just confuses the blond even more, but before he can demand answers, Balin swims back over carrying a large sheet of etchings. Setting it down in front of the other two, Fíli begins to read, Dwalin leaning over his shoulder to try and make out the markings.

“There is a life growing inside you, Fíli. You are with child.” Balin says after a few minutes of silence, Fíli’s head whipping up and giving the elder a wide-eyed look.

“There has to be some kind of mistake, Master Balin. This is just a bit of weight gain,” Fíli denies, his mind trying to wrap around their accusations.

“This started a few weeks ago?” Balin motions to his stomach. “Your appetite increasing and sickness taking hold of you? All the signs are written right here, Prince Fíli. You are with child.”

“But I’m a male! I can’t…”

“Yes, that part was a bit puzzling, though there are records from earlier times that tell of males giving birth. It was not uncommon when females were scarce,” Balin says with a nod. Fíli’s face flushes red as he shakes his head and buries his face in his hands.

“It’s because of Kíli,” Dwalin says softly from the side, Fíli’s head whipping up to stare at the bald man in confusion. Balin gives his brother an odd look, telling him without words to continue. With a glance at Fíli’s distressed face, Dwalin can only shake his head in a refusal to comment further.

“This Kíli, he is different? If we could summon him here, he may be able to help—”

“We can’t summon him here,” Fíli says quietly, hugging his tail close to his chest and unconsciously using it to cradle his stomach. “He’s human.”

Balin’s eyes widen, the elder quickly glancing to his brother and staring when Dwalin nods. Looking back to Fíli, Balin’s eyes soften at how small the heir looks curled into himself. Swimming over he settles beside the younger, wrapping a strong arm around Fíli’s hunched shoulders. “That explains quite a bit,” he says quietly, Fíli leaning into his tutor with a shaky sigh.

“Your stomach will grow quickly, the gestation period is quicker than what we’re used to. A human’s seed accelerates the body’s process, so you’ll have a little one swimming around before you know it. About three months, I’d say.” Balin says with a small smile, trying to remember where he’d put all those old etchings.

“You have to tell Thorin,” Dwalin says quietly from across the room, Fíli shaking his head vehemently as his breathing speeds up.

“No! He’ll kill Kíli, I know he will.”

“Fíli, you know we’d never let that happen.” Dwalin says, swimming over to settle on Fíli’s other side. “You won’t be able to hide it for much longer,” the warrior points out, frowning when he sees Fíli’s shoulders fall.

“I have to tell Kíli,” the blond murmurs, his thoughts turning to Kíli and how he’ll handle the news. Fíli relaxes his tail, bringing a hand up to rest over his stomach lightly. The brothers watch him silently, looking over the blond at each other and nodding in an unspoken agreement.

“We’ll have to tell Thorin first, there’s no way around it. You won’t be able to change, either. The male human body is not equipped for carrying life like ours is.” Balin tells the blond, Fíli nodding and uncurling from his perch. Resting a light hand over the blond’s stomach, Dwalin chuckles at the thought of the life inside.

“Looks like the line of Durin continues on through the impossible.”

 

* * *

 

To say Fíli’s nervous about revealing his pregnancy to his uncle is an understatement. Unluckily for him, his uncle is alone, and Dwalin hovering next to him means Fíli’s got no chance of escape. Thorin’s in the throne room looking over some sort of map that’s just been delivered, Fíli watching from the doorway and ducking away each time his uncle looks up.

Dwalin watches the prince debate internally about going inside, sighing and resting a hand on Fíli’s shoulder before swimming around him and heading towards Thorin.

“Dwalin,” the king acknowledges, Dwalin nodding in return and glancing back at the map. The bald merman looks toward Fíli, motioning him forward though Fíli shakes his head. “Is there a problem?”

“Hmm? Oh, well, I wouldn’t call it a problem…”

Thorin raises a brow, turning his full attention to his guard captain and giving him an expectant look. Dwalin shifts his gaze back to the doorway, narrowing his eyes at Fíli and deciding enough’s enough.

“Fíli has something he needs to tell you.”

“Fíli? Where’s—”

“Right here, your Majesty,” Balin’s voice comes from the doorway, the white haired merman being followed by the prince in question. Fíli gives his uncle a nervous look, and before they get too close Balin leans over to whisper in his ear.

“You mustn’t be so nervous, laddie, negative emotions are not good for the…”

Fíli nods, taking a deep breath and letting it out slowly. Thorin watches this with confusion, and when Fíli approaches, the king looks at him with a raised brow. “What’s all this about, Fíli?”

“Uncle, I have some news,” Fíli starts, wringing his hands nervously in front of his stomach.

“You’ve given up on the human?” Thorin says with a small smile, Dwalin smacking himself in the face and dragging his hand down while Balin blanches. Fíli’s eyes grow wide, and Thorin finally realizes something’s wrong. “What’s going on here?”

“I’m uhh, you see…you must promise not to get angry,” Fíli whispers, refusing to look up at the brunet. Thorin’s gaze shifts to Balin, though the elder just shakes his head and places a comforting hand on Fíli’s back.

“I will promise no such thing! What has happened? Have you been harmed? Was it the human boy, you must tell me if it was, Fíli, I will—”

“Kíli didn't do anything wrong!” Fíli shouts, angry that his uncle thinks so little of his mate. His breathing is coming quicker, and his hands drop to his stomach when he remembers what Balin said earlier. Thorin’s glare follows his hands, fixing on the almost unnoticeable bulge and staring.

“There’s…there’s a baby growing inside me,” Fíli finally gets out, voice so low Dwalin would have missed it had he not already known. Immediate silence follows the confession, and a few minutes pass before Thorin moves.

He swims over to the throne, unsheathing Orcrist from its scabbard and gripping it tightly. He says nothing, moving to swim out of the room and up to the surface. Dwalin’s quicker, having expected this kind of response and preparing for it. He moves in front of the king, quickly and carefully wrestling the sword from Thorin and letting it fall to the sand below.

“Unhand me, Dwalin! I will hunt that human down and gut him in his bed if I have to,” Thorin growls, Fíli’s distressed noise never reaching through his angry haze. Balin lays his arm over Fíli’s shaking shoulders while Dwalin gets a tight grip on the king.

“You will not!” Fíli shouts, shrugging out from Balin’s hold and swimming over to his uncle and Dwalin. “You won’t do anything to Kíli, this is no fault of his.”

“It is his fault, of course it is! He’s defiled you! Placed a burden on you that you should never have to—”

Fíli slaps his uncle across the face, the throne room falling completely silent once more. Balin and Dwalin turn wide eyes to Fíli, who’s chest is heaving as he tries t control his own temper.

“I love Kíli with everything I am, why can’t you understand? Of course this situation isn’t ideal, but neither Kíli nor I knew this could happen. The fault is no ones, please do not make this any harder.” Fíli pleads, his anger bleeding quickly to upset as tears well in his eyes. “I…I’m scared, Kíli doesn’t know yet and I…I do not mean to bring you shame.”

“Fíli, you—”

“I can’t change what’s already happened, I can only accept it and go forward. This…this baby is a gift, one that I will cherish no matter who supports me,” Fíli’s crying now, but his tears are swallowed up in the vast ocean.

Thorin sighs, Dwalin letting him loose and keeping close, though there’s no sign of anger on the king’s face now. He swims forward, placing his hands hesitantly on Fíli’s shoulders and looking him in the eye.

“There is not much that can be done but accept this. The circumstances are less than favorable, but I will support to you…and the human.” Thorin bites out the last bit, but Fíli takes what he can get. Wiping at his eyes, he nods to his uncle, reaching for his hand and slowly placing it over the tiny bump.

“At least the line of Durin will continue, right?” A small smile graces Fíli’s lips, Dwalin smirking from behind Thorin and slapping the king on the back.

“A strange way of getting what you want, isn’t it, grandda?” Dwalin laughs, Balin chuckling and giving a reassuring nod to Fíli. The blond lets out a breath, scrubbing at his eyes once more before giving his uncle a relieved smile.

One down, one to go.

 

* * *

 

Kíli rushes down to the docks the moment after he dumps their bags on the cottage floor. Dís laughs as he tries to hurriedly put things away, shooing him off with a kiss to his forehead. Kíli shouts back his thanks and tears down the beach, almost tripping over the uneven wood of the dock as he scrambles to the end.

What he doesn't expect is to be greeted by the large bald merman Fíli calls Dwalin. Frowning, Kíli kneels down and waits for an explanation, his limbs shaking in anticipation. The bald merman eyes him up, but before Kíli can start talking the merman interrupts.

“Fíli sick,” he says simply, a satisfied smile spreading over his face when Kíli’s happiness plummets. This human of Fíli’s doesn’t seem all that bad after all.

“Sick? Is he okay? Does he need anything, can I help?” Kíli stammers out quickly, eyes blown wide as his hands clench around the wood of the dock unconsciously.

Dwalin debates his next move. It would be so easy to send the human away, though the thought of Fíli’s distress earlier at not being able to meet the brunet human comes to mind. The blond hadn’t been sleeping lately, complaining of stomach pains and feeling like something was missing.

Balin had told him his body was changing to carry the child, and that expecting mates weren’t usually separated, though that wasn't really what Fíli had wanted to hear. With a heavy sigh, Dwalin makes his decision, motioning for Kíli to follow him into the water.

“Come, take you to Fíli.”

Kíli’s eyes light up as he sits back, stripping his shirt and sandals off and thanking the gods he wore his swim shorts home this morning. He slips into the cool water, easily following Dwalin out towards the open ocean.

The bald merman is impressed the boy can keep up, knowing Fíli must have something to do with the easy way the human cuts through the water. When they get above the nest, Dwalin motions for the human to take a breath, which Kíli does with an eager nod.

“Wait, you’re not going to kiss me, right?”

Grabbing his arm, Dwalin tugs the brunet under and swims quickly towards Fíli’s cave. He bypasses the main entrance to the nest, pulling Kíli through the small opening and up to the surface. They break the water quietly, Dwalin spotting the blond merman sleeping up on his side, tail swaying lazily in the water. With a finger to his lips, Dwalin nudges Kíli towards the blond and slips back under the water to find and distract Thorin.

Kíli quietly swims closer, lifting a hand up to run along the length of Fíli’s back as uses his other hand to hold onto the ledge. A cooing noise comes from the blond, Kíli grinning as he runs his hand down the length of Fíli’s smooth tail. Fíli hums happily, his eyes blinking open and glancing behind him to see Kíli.

Jerking away harshly, Fíli slips into the water before Kíli can see his stomach. His quick departure causes a huge splash, Kíli wiping both water and hair from his face as he leans up onto the ledge. Coughing the water from his lungs, the brunet turns around and tries to spot Fíli.

“Fee? Fíli?” Kíli coughs, pushing off the strip of shore and swimming out a bit to tread water as he looks for the blond. Fíli watches from a few feet below, arm coming up to wrap around his slightly bigger bulge. He didn't want Kíli to find out like this, not where he can’t dive under and leave. The blond knows Dwalin has brought his human here, trapping Fíli into telling him. With a slight grimace, Fíli drops his arm and swims up to Kíli slowly, the brunet’s voice thick with worry.

“Fíli are you okay? I didn't mean to scare you, I can get Dwalin to take me back…I think.” Kíli babbles, spinning around when Fíli surfaces behind him. Kíli reaches out for him, though he pulls back at the last minute, unsure. Flicking his tail once, Fíli leans forward into the embrace, Kíli’s arms coming to wrap around the prince in a tight hug.

“I missed you, Fee.” Kíli says softly, pulling back to kiss the blond chastely. Fíli tilts his head, tongue tracing Kíli’s lips and flicking inside to deepen their kiss. The brunet moans, one hand fisting in Fíli’s hair while the other grabs his shoulder for balance. Fíli pulls back when Kíli tries to press them flush together, the human raising his brow in confusion when they don’t slot together like usual.

“Miss Kíli,” Fíli murmurs, dipping in for another kiss before tugging Kíli back towards the ledge. Kíli can tell something’s off with the blond, and when Fíli tries to urge him up onto the ledge, Kíli stays stubbornly in the water.

“What's wrong, Fíli?” Kíli asks in a concerned voice, the blond looking away and out over the small cave. Kíli runs his hand up and down his back and with a sigh, Fíli moves to heft himself up onto the ledge.

The brunet human notices Fíli isn’t shifting on his stomach like usual, the thought of a stomach or chest wound sending Kíli closer to the blond with frantic movements. He watches as Fíli sits up, balancing himself and holding his arms out for Kíli. Swimming closer, Kíli leans on the scales of Fíli’s tail, the thick muscle of it wrapping around his legs and keeping him steady.

“Kíli,” the blond whispers, reaching for one of Kíli’s hands and brining it up to rest over his stomach. Kíli’s palm is warm over his cool skin, the slight ache there disappearing when he drags Kíli’s other hand up to mirror the first. “Feel.”

“Fíli, what’s—”

Eyes widening in shock, Kíli presses his hands lightly to the bulge and stares into Fíli’s nervous azure eyes. The blond shifts his gaze away, hands tightening slightly over Kíli’s wrists as he slowly feels around Fíli’s stomach.

“Fíli,” Kili says in a breathy voice, his fingers moving around the blond’s middle to trace the contour of the added weight in wonder. Fíli refuses to look down, his eyes welling with tears at the thought and feel of Kíli touching _their_ _child_ for the first time, though indirect as it is. He doesn't really understand why this is making him want to cry, but he can’t really do anything about it now.

When Kíli’s warm hands disappear from his stomach, Fíli closes his eyes and lets a few tears leak through. Of course Kíli wouldn’t want this, they’re both too young and too different. Before any other dark thoughts can spring forth, Kíli’s hands are cupping his face and pulling him down into a deep kiss. Fíli melts into the kiss, edging off the ledge and slipping into the water with the human.

“Hey, Fee, don’t cry,” Kíli whispers between kisses, slipping a hand down Fíli’s chest to rest over his stomach. Warmth blooms in Fíli’s abdomen as he smiles into the kiss, his hands coming up to bury in Kíli’s dark hair. The brunet wraps his arms around Fíli, who keeps them afloat with steady flicks of his tail.

“I love you, love this,” Kíli brings the blond flush against him, looking down and grinning when Fíli’s slightly enlarged stomach bumps against his own. “This is ours, we made this.”

“Love Kíli,” Fíli hums, resting his head on Kíli’s shoulder and relaxing in the warm embrace. They float in the water for a while before Fíli pushes Kíli up onto the small shore, hefting himself up to lie next to the human on his side. Kíli brings his arm up around the blond, his smile refusing to dim as Fíli’s tail sways absently through the water below.

“Does your uncle know?” Kíli whispers into Fíli’s hair, the blond nodding against Kíli’s shoulder and pressing kisses where he can reach. “Is it safe for me to be down here?” Kíli jokes nervously, remembering the angry look the large brunet merman had given him the last time he was in Fíli’s cave.

Fíli sits up, eyes flashing with a growing anger. “Kíli safe always, safe with Fíli.” Kíli nods, pulling Fíli back down and shifting to spoon snugly behind him. Fíli pillows his head on Kíli’s arm, the brunet bringing his free arm around to settle against the merman’s stomach. His hand splays wide, massaging the bulge with warm fingers that make Fíli moan happily.

“I’ve got to tell Mama,” Kíli says suddenly, Fíli nodding sleepily and nestling back into Kíli with a yawn. The blond drifts into an easy sleep, Kíli continuing to rub his growing stomach in small circles.

Kíli’s attention shifts to the water a few minutes later, lifting his head and spotting both Dwalin and Thorin watching them. Lying his head back down, Kíli refuses to move and wake the blond merman slumbering in his hold. Thorin swims over to the ledge, hefting himself up to sit next to the human in a rare display. Kíli keeps his gaze on Fíli’s head, trying not to be intimidated by the large merman sitting beside him.

“Fíli told you,” Thorin says quietly, more a statement than a question. Kíli nods his head, cupping the blond’s stomach and getting a sleepy purr in response. “You respond well.”

“I was shocked at first, but this is something Fíli and I made.” Kíli begins softly. “It doesn't matter how different we are or what anyone else thinks, I love Fíli and the proof of our love grows inside him. I’ll love both of them forever, no matter what.”

Thorin sits in silence for what feels like hours, and Kíli’s about to drift to sleep when he feels a hand carding softly through his hair. He hums at the touch, following Fíli into sleep a few minutes later.

The King looks down at the two, Kíli’s face buried in Fíli’s neck and his arm slung protectively over the baby bump. Fíli is snuggled back into the human, not an inch between them as he sleeps peacefully in Kíli’s arms. Pulling his hand back carefully, Thorin slips into the water and finds Dwalin waiting in the cave’s entrance.

“The boy is kin now, you were right from the beginning,” the brunet says as they slip through the cave, Dwalin’s grin splitting his face as he slaps Thorin on the back with a laugh.

“If only you’d listened to me earlier!”

 

* * *

 

“C’mon Mama!” Kíli laughs, pulling his mother from the cottage and down the path towards the beach. Dís chuckles at Kíli’s excitement, wondering for the hundredth time what has gotten into him since they got back from the city.

“Will you please tell me what’s going on?” Dís asks again, smiling at the feel of warm sand under her bare feet. Kíli just shakes his head and tugs her hand to move faster.

“It’s a secret, but we can’t keep Fíli waiting _forever_!”

“Oh please, five minutes is hardly forever!” Dís laughs, catching sight of the blond merman in the waters below the dock. Kíli drags her through the sand, Dís giving him a puzzled look when they walk past the dock.

Fíli sees them and grins, still a little unsure of how Kíli’s mother will react to the news. He swims closer regardless, Kíli’s easy smile setting his nervous flutters at ease. Keeping himself in the water, Fíli laughs when the happy brunet splashes into the waves and wraps him in a hug.

“I feel bad for you, Fíli. This one is driving me crazy today!” Dís smiles, Fíli giving her a grin and easily dunking Kíli under the water. Kíli comes up sputtering, shoving Fíli softly and crawling back up the beach to lie in the surf next to his mother. Fíli follows slowly, Kíli sensing his insecurity and reaching down to drag him up between his legs.

“What’s going on with you two?” Dís eyes them suspiciously, trying to keep the happy grin off her face at how easily they move around each other. She’s known for ages that they’re closer than friends, differences falling away when she catches a glimpse of the warm looks they give each other.

“Mama, we…Fíli and I are…here!” Kíli shifts the blond onto his back, reaching for his mother’s hand and brining her into the surf. Dís goes willingly, plopping down in the shallow water as Kíli draws her hand up and over Fíli’s stomach.

Dís takes in a sharp breath when her hand is placed over Fíli, her eyes widening at the telltale bulge protruding from Fíli’s middle. Bringing her other hand up, Dís covers her mouth in shock as she stares down at the noticeable baby bump. “How…”

Fíli tenses nervously, Kíli’s free hand coming up to rub his stomach where it curves outward. After a few moments Dís moves her hand, softly rubbing the bulge and feeling Fíli relax against the touch. Kíli keeps his eyes on his mother’s face, nervous excitement and worry filling him as he waits for everything to sink in.

“Mama?” Kíli asks softly, jolting Dís out of her daze and looking to her with worry. The brunette woman has tears prickling in the corners of her eyes, a happy smile breaking out over her face as she pulls them both into a hug.

“Oh boys,” she laughs happily, pulling back and pushing around Kíli to settle more comfortably next to Fíli. “How far along are you?” She asks Fíli, her hand hovering unsurely over the bump as she locks eyes with Fíli’s deep blue ones.

“Month I think?” Fíli answers with a smile, wrapping his hand around Dís’ and guiding her to place it on his stomach. Dís coos happily, rubbing circles into his skin and giving both boys a knowing smile.

“You’ll have your hands full in eight months or so,” Dís laughs, remembering when Kíli was a tiny ball of energy, undaunted by almost anything in his path.

“Two months,” Fili pipes up, both Kíli and Dís turning to look at him with shocked expressions, hands stilling on the bulge. “Only two left.”

Kíli lets out a choking noise, Dís shaking her head and pulling her hand back to clap them together. “There’s so much to do! I have to go clean out the spare room!” She gushes happily, leaning forward to place a kiss on Fíli’s head, then Kíli’s. “I’m so happy for you both! I can’t wait to be a grandmother!”

Giving out one last hug, Dís shoots them a loving look and heads back towards the cottage. Fíli waves to her until she disappears from sight, collapsing back into Kíli and bringing his hands up over his stomach. The brunet lets out a low whistle, his own hands coming up to rest lightly over Fíli’s.

“Two months, huh?” He murmurs into blond hair, his hands moving lower to stroke the smooth skin right above Fíli’s scales. The merman tips his head back onto Kíli’s shoulder, a low moan spilling from parted lips. “We’re going to be parents in two months,” Kíli whispers into the blond’s ear, his hand wrapping around Fíli’s erection when it eases out of the sheathe.

The water laps around them, cool liquid swirling around Fíli’s cock and sending pleasant shivers through his whole body. Kíli smirks, his hand pumping in a lazy rhythm as he bites Fíli’s shoulder softly. “Kíli please, ughh!”

“So sensitive, Fee.” Kíli chuckles as he twists his hand, changing the pace of his strokes from fast to slow. Sitting up, he lets go of the blond and laughs at the urgent whine that spills from the merman. Shifting Fíli out of his lap and into the water, Kíli leans over and tightens his hand into a warm tunnel that Fíli bucks up into. “You like that?”

“Kiliiii,” the blond merman moans, his hands digging into the sand below him as his tail splashing around in the water. “Fuck me,” Fíli pants, lidded eyes connecting with Kíli’s dark brown in a sensual plead.

“Mmm, I think that’s what go us into this,” Kíli grins, fisting Fíli’s cock with fast and tight strokes, swirling his wrist and palming around the head when his slides his hand up. Fíli moans when Kíli changes his movements, tail thrashing around in the water as his hips buck awkwardly to thrust into the brunet’s hand. Kili leans down to kiss the merman’s neck and shoulder, sucking a dark bruise into the skin of his throat.

He continues to get Fíli off, taking in every sigh, moan, and whisper coming from his blond lover. Kíli uses his free hand to trace light fingers over the blond’s stomach, Fíli’s breathing hitching as he throws his head back into the water with a loud moan.

“C’mon Fíli, come for me,” Kíli whispers, squeezing his hand around the blond in a tighter grip.

With a sharp keen Fíli comes, hips stuttering into Kíli’s hand as he rides through his orgasm. Kíli slows his movements, settling back on his heels and taking in Fíli’s flushed skin and swollen belly all laid out for him. After a few minutes of heavy breathing, Fíli’s spent arousal slips back into his sheathe, Fíli lifting his arms out to the human. Kíli chuckles, pulling the sated merman back against his chest and ignoring the way his own erection rubs teasingly against Fíli’s back.

“Kíli turn?” The blond asks lazily, making no move to get up from the comfortable embrace. Kíli laughs against his neck, licking the shell of his ear and tracing random patterns on Fíli’s stomach.

“I’m okay, Fee. Dwalin will be here soon, anyway,” Kíli says, leaning back into the sand and smiling down at the merman. Fíli plays with Kíli’s fingers, his tail flicking through the water idly as they wait. Thorin had demanded Fíli be escorted to and from the surface while pregnant, something the blond hated with a passion. Usually it was Dwalin, though sometimes Thorin himself brought the blond to and from the beach.

The familiar sound of someone breaking the surface draws both their attention, the bald merman swimming closer with a hand over his eyes. “Is it safe? No more sex!”

Fíli snorts, reaching for a handful of wet sand and lobbing it at the other merman. Dwalin laughs and removes his hand, dipping under the water to wash the dark sand from his chest as he comes closer to the two. He narrows his eyes on Fíli’s easy smile and relaxed sprawl, rolling them and huffing out a laugh. “So? Good or bad?”

“Very good,” Fíli says with a nod, lifting his hand in a ‘thumbs up’ gesture that’s lost on Dwalin. Kíli tries to hide his laughter in Fíli’s hair, the warrior narrowing his eyes playfully at the human.

“Hope child takes after only you,” Dwalin tells a laughing Fíli, the brunet human squawking out insults as he helps Fíli shift further into the water. Dwalin gives Kíli a grin before ducking under, giving the two a bit of privacy to say their goodbyes.

“What if he’s right? What if he doesn't take after me at all?” Kíli asks in a worried voice, Fíli giving him a grin as he leans in to peck pouting lips.

“She half you, half me,” Fíli says with a nod, Kíli giving his belly one last rub before shifting back.

“She? How do you know it’s a girl? I think it’s a boy!” Kíli leans in for one last kiss, Fíli refusing to answer as he ducks under the water to follow Dwalin back to the nest.

Kíli stands in the surf for a few minutes, watching the sun sink lower and lower into the water. Shaking his head, he trudges up the beach and towards the cottage, wondering just how crazy his mother is going with the spare room.

 

* * *

 

**Notes for the Chapter:**

> I hope the reactions are okay, I added Thorin's at the last minute, I originally had them in the cave when Kíli finds out and when he asks if Thorin knew, Fíli just nodded. But...I thought some of you might like to see his reaction. I think maybe he's still mad about it but knows Fíli doesn't need the added stress? I'm sure he comes around to the idea completely at some point.
> 
> And Dís...I love her as a supportive super Mama so of course she'd be thrilled. I imagine she was young when she had Kíli, so she understands that part.
> 
> Okay well, there it is. I hope I didn't disappoint, and I'll continue working on editing the next bit between drabbles.


	3. Bundle of Joy

**Summary for the Chapter:**

> After a long three months, Fíli and Kíli's patience finally pays off.

**Notes for the Chapter:**

> I've taken quite a few liberties writing this mer-pregnancy and how it happens, so I'm sorry if anything is a little too much or too out there.
> 
> This chapter was such a pain I almost scrapped everything. There's not as much dialogue as I wanted during the parts about the pregnancy, but I think it turned out okay.

* * *

 

During the last two months of Fíli’s pregnancy, Thorin forbids the blond from going to the surface altogether. He doesn't just come out and say this, instead keeping both himself and Dwalin busy during the day so no one can take the blond up. Only a select handful of merfolk from the nest know who the father of Fíli’s child is, and Balin visits him for a checkup almost every other day.

Fíli’s baby bump begins to grow rapidly after the first month, and the cravings and mood swings Kíli’s mother warned him about start around that same time.

“It’s cute,” Kíli smiles, pressing kisses to the growing bump of Fíli’s stomach, the blond’s hand tightening in his hair and tugging sharply.

“Not cute, big. Hungry a lot,” Fíli grunts, tail splashing in the shallow water and soaking Kíli. The human pulls back with a laugh, rubbing small circles into the stretching skin and leaning up to give Fíli a kiss on the cheek.

“You’re eating for two now, Fee.”

The cravings early one morning, when the blond informs Kíli of his absolute dire need for carrots. Fíli’s been craving them for hours, almost calling out to Kíli in the middle of the night. When he goes up the next morning, Dwalin gives the human a sympathetic look before ducking back down, Fíli latching onto Kíli’s legs with a whine for the orange vegetable.

Kíli’s always had a hard time denying Fíli anything.

Fíli later mumbles, out of the blue and through a mouthful of carrots, that he will deliver the baby up at the beach, where he can be with Kíli. Kíli is relatively surprised, since Thorin had gone on and on one day about how dangerous the delivery could be, that Fíli would be safer delivering in the small cave under the water. Kíli nodded his agreement, Fíli’s safety coming before his own want to be with him when the baby comes.

Shutting his uncle down doesn’t even make Fíli blink, Dwalin dragging the protesting king under the water as Fíli cuddles up to the human.

After that, Fíli’s visits to the surface become less frequent, Thorin doing his best to keep the blond below the waves until he delivers. This doesn’t work as well as Thorin hoped, though Fíli doesn’t come up as often as he wants.

Dwalin has been able to bring the Kíli down a few times, though the upcoming fishing season keeps the brunet busy working on Bofur’s boat and in the shop during most days. Dís has taken to painting the spare room, although Kíli isn’t sure how much time the baby will spend there. When he voices this to his mother, she only nods and tells him it’s better to be safe than sorry.

Stepping into the newly cleared out room, Kíli smiles at the beautiful murals covering the walls. Dís, along with Bofur, Ori, and Bilbo, the teashop owner, have painted three of the room’s walls with a beautiful underwater scene. Colorful fish fill the walls, along with bright corals and even a few dolphins in the distance.

Bofur had joked about adding a few mermaids, Ori telling Kíli later he would add them if they ever wanted him to. Kíli had saved the last wall for himself, planning with Bilbo and Ori to make sure it was just right.

Looking at it now, he can’t be happier at the finished product. It’s a prefect replica of the beach and dock where he and Fíli spend so much time, the image flawless down to the last uneven plank of wood. Kíli walks over and runs his hand across the wall, his eyes catching on the image of a small boat floating in the water near the corner.

Stepping closer, his eyes widen as he takes in the man sitting happily on the boat. His father has been painted perfectly, with messy dark hair and a mischievously happy grin that Kíli can still recall. Wiping his eyes, happiness settles in Kíli’s chest as he thinks of bringing Fíli and their child into the room.

Dís appears in the doorway quietly, leaning against the wood and watching her son take in the new room. She watches as he wipes at his eyes, looking up and catching her with a happy smile. Dís walks forward and wraps her arms around Kíli, the brunet letting out a quiet sob into her shoulder. Bringing them down to sit on the floor, Dís holds Kíli close as he shakes against her chest.

“It’s perfect, Mama,” Kíli sniffs, squeezing the brunette woman tightly before leaning back and wiping at his eyes. Dís gives him a watery smile of her own, reaching forward to take his hand and squeeze it tightly.

“Your father would be so proud of you, Kíli, of the man you’ve become. I’m sure he’s watching right now, laughing at us sobbing like babies.” Dís chuckles, Kíli tipping his head back and laughing at the thought. His father always loved to tease, Kíli often helping to rile his mother up before they both escaped to the beach until dinner.

“He’ll watch over you and Fíli both, and the new bundle you’re bringing into the world.” Dís smiles softly, rubbing at Kíli’s shoulders before moving to stand. Kíli follows her up, pulling his mother into a tight hug.

“Thanks, Mama. I know Fee will love it.”

Bringing Kíli’s head down for a kiss, Dís pulls back, heading through the doorway to start dinner. Making his way out of the room, Kíli gives the walls one last smile before shutting the door softly behind him.

 

* * *

 

Kíli gets endless enjoyment out of staring at Fíli’s growing stomach, something the blond just can’t figure out. Fíli enjoys the attention though, mostly because it usually leads to Kíli pressing warm kisses all over his body and most of the time finishing Fíli off if he slips out of his sheathe.

Fíli, Kíli figures out, gets more easily aroused as his pregnancy progresses. With only a few well-placed touches and words, Kíli can have the blond merman falling apart in his arms, much to his amusement. They never have actual penetrative sex, something Fíli gets frustrated with early on. Kíli refuses to take Fíli, for fear of causing any harm to the bundle of love growing within the blond.

He manages to satisfy the merman with his fingers or mouth, so Fíli can’t really complain too much. Fíli also doesn’t last very long during their trysts, something that has Kíli grinning smugly. Although after he first points it out, Fíli does nearly bite a chunk out of his shoulder. Kíli decides to keep those kinds of comments to himself, along with his observations of how large Fíli’s stomach is growing.

Along with the easy arousal comes the more violent tendencies, and while they should frighten Kíli, he can’t help but smile softly when Fíli rips into his live dinner like a great white shark. Kíli does flinch, however, when Fíli insists on sitting in his lap as he tears into the fish he eats, small flecks of cold flesh landing on Kíli’s face and chest. He grins and bears it, although he may be shuddering for a different reason than Fíli thinks when the blond kisses him after his meal.

Possessive protectiveness also takes a hold of Fíli after the first month, the need of wanting to keep Kíli close and away from others is something he struggles with due to their differences. When Kíli heads to the beach after working with Bofur, Fíli growls dangerously as he approaches, smelling the other people Kíli’s worked with or stood by that day. He even snaps at his uncle and Dwalin a few times, if they say something that goes a little too far or if Dwalin does his usual mussing of Kíli’s hair.

The first time the bald merman had gone to do it after teasing Kíli, Fíli had almost bitten his hand.

‘Woah, Fee! What’s the matter?” Kíli gaped, Fíli wrapping his arms around the human and dragging him deeper into the water, growling lowly with black eyes focused on Dwalin. When he struggled against the blond’s hold to try and swim on his own, Fíli’s nails dug into his arm.

“He’s protecting you…from me,” Dwalin grinned, amused at the prince’s reaction. Kíli sputtered around the water, slipping further and further down into the ocean as Fíli drug him along.

“He’s going to drown me if he keeps it up!” Kíli mumbled, bringing his hand up and placing it over Fíli’s stomach lightly. “Fee, you need to blurbbb—”

He slipped under before he could finish, heavy work clothes and boots pulling him down quickly. Fíli’s whine reached his ears even under the water, Kíli stalling his flailing limbs as the merman approaches quickly and grabs his hand.

When they break the surface, Fíli’s wrapped around every inch of Kíli, leaning close with his stomach budged up against the brunet’s. “Sorry, sorry Kee.”

“It's okay, I’m okay,” Kíli breathed, moving back to the shallows and pulling a nervous Fíli into his lap. Fíli cups his face and tilts it from side to side, as if Kíli’s taken some kind of head wound. The brunet’s eyes shift to Dwalin for answers, though the bald merman just shrugs.

Pulling Fíli back against his chest, Kíli rubs his stomach softly, eliciting a low purr from Fíli. He relaxed fully into the brunet, tail flicking in the water happily as he relaxes back into Kíli, the assumed threat now at the back of his mind while he enjoys Kíli’s attention.

* * *

  

A few weeks before Fíli’s due, Kíli finds him swimming around the shallows in agitated circles. Slipping his sandals off, the brunet heads out to the end of the dock and plops down, swinging his legs over the edge and into the water while he waits for Fíli to notice him.

Fíli bursts to the surface with a pained look, barely lifting himself out of the water and sending Kíli into a panic.

“What’s wrong? Is it the baby, are you okay?” The brunet babbles, leaning over the dock and reaching out a hand to run through Fíli’s hair. Turning into the touch, Fíli’s face relaxes when Kíli’s voice washes over him. Pulling back for a few seconds, Kíli slips into the water next to the blond and ducks under to press a kiss to Fíli’s swollen belly. It’s almost as large as a human woman’s pregnant stomach, and Kíli already loves everything about the baby inside. He surfaces, pushing the wet hair from his face and leaning forward to kiss the blond.

“Hmmm, better,” Fíli murmurs against Kíli’s lips, dragging the brunet towards the shore. Lying on his back, Fíli hums when Kíli straddles his tail, rubbing circles on the tight skin stretched around their child. Kíli does his best to soothe the blond, knowing Fíli desperately misses swimming together with Kíli lying on his chest. Massaging Fíli’s stomach, Kíli’s head shoots up in surprise when he feels something bump against his hand from the inside.

“Fíli, did you feel that?!” Kíli whispers excitedly, his hands feeling all over for another bump. “C’mon baby, kick for daddy again,” Kíli coos to the blond’s stomach, Fíli giving him a sharp look that turns bewildered when he feels the baby move as if on command.

“That's my boy!” Kíli laughs, leaning over to kiss the blond without removing his hands. Fíli grunts at the next kick, Kíli smiling as he leans back down to press warm lips to the blond’s stomach. “Okay little prince, I think Mama’s had enough,” Kíli grins, Fíli reaching down to swat him for the ‘Mama’ comment. Kíli ducks out of the way, his grin morphing to something softer as he rubs the blond’s stomach and begins to sing his mother’s lullaby.

Fíli joins in halfway, translating the words in his own language as they calm the restless baby. Kíli shifts off the blond, lying on his side next to Fíli and cuddling close.

“I want you to have him where it’s safe, it doesn't matter if I’m there or not.” Kíli tells the blond, Fíli huffing and shifting his tail in agitated movements below them. “I want you both to be safe, okay Fee?”

Fíli remains quiet, but after a long while he shifts onto his side lightly and stares into Kíli’s warm brown eyes. “Okay,” he breathes, Kíli’s smile lighting his face as he moves to kiss Fíli on his forehead. “Kíli come?”

“Of course I’ll come, no matter what, okay? You just focus on keeping safe,” Kíli promises, bringing an arm up around Fíli and rubbing his thumb along the smooth arm. Fíli leans in for another kiss, his hand reaching up to intertwine their fingers across his stomach.

“How are you feeling?” Kíli breaks the silence, Fíli looking up and giving his best shrug.

“Feels like whale, swim bad. Heavy,” Fíli mutters, his tail flicking in the water and sending a spray up to splash them both. Kíli smirks at him, untangling their hands and sitting up. Fíli watches him tiredly, huffing when Kíli grabs his tailfin and pulls him down. Using his hands to push himself down, Fíli slips under the water and stretches out his arms and tail.

Kíli’s standing in the deeper water a few feet away when the blond pops back to the surface, crooking an inviting finger at him. Fíli gives a feral grin, ducking under and swimming as quickly towards Kili as fast as his large stomach will allow. He makes it to Kíli faster than he thought, yanking the human’s legs out from under him playfully. Kíli lets out a shout, toppling into the water and flailing his arms about. Fíli wraps his arms under Kíli’s, the brunet stilling his movements as Fíli drags them up and out a bit deeper.

“You’re still plenty fast,” Kíli muses, a stupid smile spreading across his face at the feel of Fíli’s stomach pressed to his back. Fíli takes them out to the end of the dock, wrapping the end of his tail around Kíli’s legs to hold him in place. Leaning forward, Fíli pulls him into a deep kiss and under the water, Kíli breaking away and breathing easily under the waves.

He takes in the sight of Fíli’s stomach in his natural environment, noting the slight changes the blond makes as he pulls Kíli along next to him. Fíli swims just as easily as before, his body automatically countering the weight in his middle and adjusting around it. Kíli finds him even more beautiful under the water, golden hair floating around his head and mixing with Kíli’s own dark locks. Kíli wonders absently if their child will have Fíli’s golden hair or his own dark brown.

Fíli tugs at his hand, bringing the daydreaming human out of his thoughts and into the present. Kíli gives the blond a sheepish smile, pulling Fíli close and wrapping his arms around broad shoulders. Fíli hums happily, his gaze going from Kíli to the merman approaching from behind.

Squeezing Kíli to his chest, Fíli shoots up to the surface and towards the beach. Wrapping himself around the brunet, he whines when he hears Thorin break the surface behind them. Fíli buries his face in Kíli’s neck, twining his tail around Kíli’s ankle and trying to hide from the larger merman.

Kíli laughs at the antics, giving the blond’s uncle a smile before squeezing Fíli tightly. Thorin watches his nephew with a small grin, Kíli easily holding and shifting the weight to keep Fíli comfortable and happy.

“Fíli,” Thorin’s deep voice comes after a few moments, Kíli doing his best to untangle himself from the clingy merman. With a huff, Fíli pulls back, his pout making Kíli’s grin crack into peals of laughter.

“Time to go, Fee. Play nice and maybe you can come back tomorrow,” Kíli tells him, shooting a hopeful look to the brunet merman. With a sigh, Thorin nods his agreement, Kíli’s smile widening as he leans forward to peck Fíli on the lips. Dipping down further, he gives the blond’s stomach a kiss and mutters against it.

“You be good now, no more doing flips in there tonight. We’re all very excited to meet you, so you be sure to come out soon, okay?” Fíli runs his hands through Kíli’s wet hair, brushing the tangles out as his one speaks to their child. With one last kiss, Kíli pulls back, ushering Fíli towards his uncle with a soft smile.

“You take care too, okay Fee?” With a nod from the blond, Kíli sits back in the water and watches Fíli depart his uncle.

“Love you, Kee,” Fíli calls before ducking under the water, leaving Kíli with a stupidly happy smile on his face.

 

* * *

 

The week goes by smoothly, Fíli coming up about every other day to spend time with Kíli. Sometimes Thorin or Dwalin stay for a while, listening to their conversations and sometimes adding in their own thoughts. They talk about random things; will Fíli teach him to swim? _He’ll already know how to swim, he’s a mer!_ Will he have legs when his tail dries out? _Most likely, but Balin might know more_. What if he doesn't look anything like me? _It’ll be a blessing!_

Kíli’s finishing up at Bofur’s shop a few days later, moving the last crate of tackle boxes to the back and laughing at Ori’s new joke. Kíli snags a bottle of water, chugging it down with the ferocity of a starving man. They look up when the door slams open, Kíli spilling water all over himself as Dwalin stumbles in, clad only in a pair of shorts and covered in sand.

“It’s time,” he breathes out, Kíli scrambling around the counter to follow the bald man towards the beach. Dwalin is much better on legs than Fíli is, though Kíli doesn't let his mind wander much further than that as they see the small group gathered on the beach.

Kíli runs down into the surf to be next to Fili, only to be snagged around the middle and hoisted away from the blond. Not a second later, Fíli’s hand lashes out where he would have been sitting, pitch black eyes flashing as an inhuman snarl rips from his throat. Kíli flinches back, though a second later he’s straining against the arm around his middle to try and reach Fíli.

“Fíli!” Kíli shouts, the blond’s head snapping up in his direction. Fíli’s snarls continue, though his eyes flash azure for a split second as he recognizes Kíli.

“Stop! You can’t—” Thorin barks, holding Kíli around his middle and ignoring the sharp elbow sent into his stomach.

“He needs me!” Kíli shouts, a low whine breaking through the growls and hisses spilling from Fíli’s mouth. An unfamiliar white haired merman nods hesitantly to Thorin, who retracts his arm and watches Kíli drop into the sand and crawl towards his nephew.

“Hey, Fee, you’re doing great,” Kíli says softly, budging up right next to Fíli and never noticing the sharp nails that prick his skin when Fíli grabs for him.

“Keeeee,” the blond merman groans, thrashing tail being held down by a now mer Dwalin. The white haired merman is speaking to Fíli from the side, hands under the water as he tries to help the delivery along. Kíli shifts to a sitting position, Balin, he remembers absently, nods to him in understanding.

Kíli digs his heels in the sand, carefully helping Fíli sit up and lean back between Kíli’s bent legs. He holds the blond’s hand tightly, his blood running down their intertwined hands and slicking their palms.

“Just a bit more, Fíli. We’re going to meet the baby soon,” Kíli soothes the blond, bringing his hand up to push back blond hair from Fíli’s face, his hand catching on a small silver bead embedded in the golden locks.

Fíli hisses when someone else joins them, though it turns into a pained whine as blood clouds the water. Kíli can hear his mother speaking with someone, though his eyes focus on all the blood in the water.

“Push, Fíli!” Balin orders, the blond thrashing his head from side to side as his tail tenses and contracts. Fíli growls and hisses, Kíli squeezing his hand and softly singing a lullaby in his ear, though he’s not sure if Fíli can hear it. With one last scream Fíli goes limp, Kíli looking up anxiously and not believing the smile spreading across Balin’s face. Dwalin sits back with his own smile, shaking his head and looking down at the baby Kíli can’t see.

“It’s a girl,” the old merman tells them, Fíli’s chest heaving as exhaustion sets in. Kíli still can’t see the baby, who is carefully handed to Thorin while Balin sets to work on Fíli’s lower half. The blond’s tail spasms a few times, Fíli turning his head into Kíli’s chest with a low whine. Cracking his eyes open, Fíli shifts tired eyes to Kíli and mouths silent words to him.

Leaning down carefully, Kíli buries his face in Fíli’s hair and brings their clasped hands up to his chest. “You did it, Fee, she’s here,” Kíli murmurs, the blond shifting his head and looking down at Balin and his uncle. Thorin looks up, giving them both a genuine smile as he holds his granddaughter below the surface.

Shifting carefully away from Kili, Fíli slips further into the water and submerges. Thorin ducks down as well, the fading sunlight casting a reflection on the water and obscuring the mermen from view. Kíli sits frozen on the beach, an unknown fear gripping his heart as seconds tick by. Dís comes to sit next to Kíli, pulling him sideways into a hug and whispering soothing words in his ear.

After what feels like an eternity, Kíli feels a tug at his ankle and looks down with watery eyes. Crawling deeper into the water, his fears vanish when he lays eyes on his daughter for the first time.

Fíli surfaces up to his neck, holding the baby close to his chest. Her dark hair is a spitting image of Kíli’s own, and her tiny tail a shade darker than Fíli’s. Kíli reaches out to brush his fingers across her head, a happy coo and a few bubbles coming from the baby’s mouth.

“Fee, she’s beautiful,” Kíli whispers in awe, turning his gaze up towards the blond merman to mirror his smile. Fíli’s hand comes up to pull Kíli a few feet deeper, moving close and passing the baby over to the stunned brunet.

Kíli brings his arms up automatically, cradling his daughter carefully as Fíli leans his head onto his shoulder. The baby squirms, Kíli moving her to the crook of his elbow and inhaling sharply when she opens bleary eyes. Bright blue eyes, a perfect match to both Fíli and Thorin’s, stare up at him before a yawn forces her eyes closed once more and she settles comfortably against her human father.

“Half you, half me,” Fíli echoes next to him, eyes shining happily as he wraps his arms and tail around his family. Kíli’s tears slip down his face silently, his gaze shifting up to his mother sitting on the beach.

“Mama, she’s beautiful,” Kíli whispers, Dís nodding and wiping at her own tears.

“Of course she is, look at her parents!” Dís laughs, Dwalin and Thorin popping up with soft laughter of their own. Dís wades into the water a few feet, Fíli looking up and nodding at her to come closer. Dwalin helps the human woman out into the water, Dís completely melting at the sight of her granddaughter.

“She’s perfect, you two. You did a wonderful job,” Dís coos, leaning over to give Fíli a kiss on the head. The blond smiles, nuzzling his face in her neck and letting out a tired sigh. Thorin puts an arm around Fíli, the blond sagging into him as he stares down at his daughter fondly.

“What are you going to name her?” Dís asks quietly, Fíli and Kíli sharing a surprised look. Dís laughs at this, shaking her head and brushing light fingers over the baby’s hair. “Don’t worry, you’ve got time.”

They stay in the water as the sun dips below the water, Fíli and Kíli taking turns holding their daughter and proudly showing her off. The night stays warm, which Kíli is happy for as he relaxes on his back, head pillowed up out of the water by his shirt and an old blanket his mother has brought down.

The baby sleeps on his chest under the calm water, small hands clenching and unclenching as Kíli lays a warm hand over her back. Kíli whispers goodbye to his mother as she takes her leave, the brunet already set in staying in the shallows with Fíli and their daughter for the night. Thorin and Dwalin are both stationed out towards the end of the dock, refusing to do anything but keep watch over the small family.

Fíli’s swimming in wide circles around the dock and cove, per Balin’s orders to keep active. His body and tail will heal fairly quickly, but the blond has to keep his blood moving for a while after the birth to avoid complications. Nodding to Dwalin, Fíli swims up towards the beach, smiling at the sight of Kíli and their daughter.

“Still asleep?” Fíli asks, sliding up next to Kíli and looking down at his two favorite people with a fond smile. Kíli hums in affirmative, lifting a hand up to bury in Fíli’s wet hair and scratch at his scalp. Kíli moves onto his side, carefully shifting the sleeping mermaid onto Fíli’s chest as he lies in the same position Kíli was in earlier. The baby makes a few fussing noises, Fíli quieting her with soft humming.

The tiny mermaid squirms on Fíli’s chest, her little mouth latching onto his nipple and causing the blond to startle at the feeling. Kíli chuckles, running his hand down the baby’s back and looking to Fíli in question.

“What’s she doing?” Kíli asks softly, Fíli shrugging and settling his back deeper into the soft sand. His tail curls up, the flat fin coming up to rest lightly along the baby’s back when Kíli pulls his hand away. Giving the two a fond smile, Kíli leans down to catch Fíli’s lips in a kiss. “You did a great job, Fee.”

“Had help,” Fíli yawns, the weariness of delivery catching up to him, though he refuses to fall asleep. “She needs name.”

“Mmhmm, how about Nerín?” Kíli suggests randomly, pulling the name floating in his mind to the forefront. Fíli hums against him, looking down at their slumbering daughter and testing out the name.

“Nerín, of sea and land,” Fíli repeats, translating the words in his own language and whispering them to his daughter. Nerín stirs against him, whimpering quietly until Kíli brings his hand up and slips it beneath Fíli’s tail along her back.

The merman begins to sing softly, lulling Kíli into a drowsy haze as they cuddle close together. Nerín coos in her sleep, Fíli’s eyes drifting closed to the steady heartbeats of his family.

* * *

 

**Notes for the Chapter:**

> Nerín is the name I came up with and thought worked pretty well. It's kind of girly, yet Kíli wanted to honor Thorin with the name of their first child...and since she wasn't a boy like he thought...
> 
> I hope this chapter was enjoyable! Now I get to write all kinds of cute baby fluff~! :D


	4. Learning

**Notes for the Chapter:**

> Have some adorable baby fluff~! *tosses hearts and glitter into the air*
> 
> I'll admit that this is a bit of a filler chapter, I need to get Nerín a bit older but I didn't want to pass up all the cute baby things. 
> 
> I know there's no way human babies this age can do some of these things, but Nerín's half mermaid so she's going to grow a bit faster than normal...ish.
> 
> Enjoy!

* * *

After Nerín is born, Kíli spends almost all of his time down at the beach. Fíli has to hiss and growl at him to go home and eat something, ignoring Kíli’s pleading eyes and pushing him up the beach. The brunet runs the whole way home, takes a quick shower, and is back down on the beach with a sandwich hanging from his mouth in less than thirty minutes. Fíli gives him an unimpressed look when he splashes back into the water with a smug smile, shooing Fíli off to go get something of his own to eat.

“Stubborn human,” Fíli huffs loudly as he hands Nerín over to the brunet, Kíli completely oblivious to the taunt as he coos happily at the big blue eyes watching him. Nerín coos back, letting out a yawn and wiggling around in Kíli’s arms.

Fíli kisses Kíli deeply to pass the magic, the brunet leaning back to lie down in the water and shifting the baby onto his chest, Nerín falling asleep almost instantly.

Nerín sleeps amazingly easily, the heartbeat of her parents working ridiculously well as a lullaby. She’ll fall asleep against anyone, Dís, Thorin, and even Dwalin are all happy victims of the mermaid’s adorable sleeping custom. 

She does, however, have a few heartbreaking crying spells, which end up being mostly late at night. There are some when Fíli realizes early on that he isn’t what she wants, so he wraps her in a soft kelp blanket and takes her up to the shore. Kíli’s always there within minutes, and neither of them talk about just how he knows to come. Thorin reasons that the bond is what causes this, but Kíli tells Fíli one night that he just _knows_.

Kíli is, by far, Nerín’s favorite pillow. When Fíli brings her to the surface during her fits, she’s out like a light seconds after Kíli cuddles her onto his chest. Fíli, in turn, curls around Kíli, each member of the small family drifting into a much-needed sleep. They’re not sure what causes it, be it the changes of Fíli’s body during the pregnancy or the amount of times they’ve used the magic, but Kíli can now remain completely submerged underwater for just under three hours.

This comes in handy quiet often, and somehow Kíli’s able to wake up just minutes before it wears off.

Over the next few months the new parents start to learn the habits, likes, and dislikes of their daughter. She loves eating the mushy food Kíli calls applesauce, but will immediately spit out the tiny pieces of shrimp Fíli tries to feed her.

Kíli always makes a face when Fíli rips into a fish with his fingers, popping chunks of it into his mouth and chewing them up before feeding the mush to the happy baby. Nerín usually ends up with half the food on her face as she tries to imitate Kíli’s disgusted look, squirming for Kíli and smearing the mush all over her father’s chest.

“Nerínnnn! Yuck!” Kíli laughs, scooping Nerín up and walking deeper into the water. When he’s in up to his waist, Kíli lifts his daughter up in the air, blowing raspberries on her stomach as he walks a few feet deeper.

Fíli smiles from the shallows, swimming up behind Kíli and resting his chin on the brunet’s shoulder, watching Nerín giggle happily. This becomes a kind of game for Nerín, the promise of playing a way to ensure she eats most of her meal.

When she’s eight months old, Kíli can’t believe how fast she’s learned to swim. Fíli tries to explain that all merfolk must learn to swim early to avoid danger, and Kíli becomes a little upset.

“But what kinds of dangers are we talking about? I don’t understand.” Kíli frowns, reaching over the floating playpen and running a hand along the mermaid’s back. Nerín coos happily, babbling in a mixture of mer language and random baby noises.

“Sharks, barracuda…humans.” Kíli’s head snaps up at the last word, eyes narrowing as he pulls his hand back sharply. Fíli sighs, flopping back into the water and splashing the both of them. Nerín giggles, squirming onto her back and reaching down to grab onto her own tailfin. Pulling it up towards herself, she laughs and tries to fit the fin into her mouth.

“I wouldn’t ever hurt you, Nerín,” Kíli promises with a weak smile, shifting his hand back down to tickle her stomach and sending Nerín into a fit of squealing laughter. He pulls back, looking out at the water and spotting Fíli swimming beneath the dock. Shifting back from the surf Kíli sits in the sand and pulls his knees up to his chest. Wrapping long arms around his legs, he stares down at his feet and frowns for the first time in a long while.

Out in the water, Fíli shakes his head and mumbles soft curses to himself. He hadn’t meant to hurt Kíli’s feelings, but what he said was true. From a very early age, all merfolk are warned against humans, though not exactly forbidden from going to the surface.

Fíli glances up towards the beach, frowning when he sees Kíli sitting on the sand with a vacant stare. The brunet is murmuring quietly to a fussy Nerín, though he isn’t making any moves to go towards her. Scoffing, Fíli swims towards the surface and slaps his tail against the waves to get the brunet’s attention.

“Kíli, stop now.” Fíli orders, scooping Nerín from the water when Kíli refuses to look up at him. Hauling Nerín and himself up onto the beach, Fíli shifts the small mermaid into Kíli’s arms and grins at the wide-eyed expression Kíli gives him.

“Fíli! You can’t just take her out of the water like that! We don’t know what’ll happen if she gets too dry!” Kíli scrambles onto his feet, Nerín cooing happily and bouncing in his arms as he carries her back into the water. Holding her close to his chest, Kíli dunks them under and surfaces to kiss her dark hair softly.

The brunet looks to the shore, Fíli giving him a smug smile as he slips back down into the waves. “Kíli keep Nerín safe, always.” The blond says when he surfaces next to them, leaning over Kíli’s shoulder to kiss Nerín’s forehead. The brunette crosses her eyes to try and track his movements, sending both her parents into quiet laughter.

“Sorry, Fee. I just want Nerín to be safe,” Kíli murmurs, leaning back into Fíli and grinning when the blond reclines them both to lie flat. Wrapping an arm around Kíli’s back, Fíli uses his tail and arm to make sure Kíli stays afloat, a happy Nerín perched on the brunet’s chest.

“Nerín loves daddy,” Fíli coos to the baby, grinning when the human tugs at his hair from under the water. Nerín lies on Kíli’s chest comfortably, her tiny tail flicking back and forth in the few inches of water around her.

“When do you think she’ll start to talk? She’s really smart already,” Kíli wonders, watching as Nerín flicks her tail and sends water towards Fíli. With a giggle, she does it again and buries her face deeper into Kíli’s chest when Fíli flicks water back at her.

“Soon, human tongue later, mine first,” Fíli replies with a shrug, saying something to the baby in his own language. Nerín responds, though her reply doesn't have the same musical tune Fíli’s has, at least not yet.

Fíli turns to him with a wide grin. “Has odd pitch, different. Gets from you, your talk.”

“She...she talks differently because of me?” Kíli asks, confused. He glances down at Nerín and sees that she’s stuck half her fist into her mouth and is chewing happily.

“Learns from you, hearing you talk,” Fíli explains, a smile blooming across Kíli’s face at the words. Bringing his hand up to rest on Nerín’s back, Kíli turns and presses a kiss to the side of Fíli’s mouth.

“I’m gunna teach her to swear like a sailor when she gets older,” Kíli grins, the blond merman scoffing and leaning over to catch Kíli’s lip between his teeth. Sucking lightly, Kíli’s soft moans are swallowed in a kiss while Nerín drifts to sleep atop his chest.

* * *

 


	5. Chapter 5

**Summary for the Chapter:**

> Little Nerín is just loves to surprise her parents ♡

**Notes for the Chapter:**

> I imagined a lot of Aidan/Kili's adorable puppy face in this chapter ;)
> 
> Big thanks to Legolaslover1 for the beta! <3
> 
> Enjoy~!

* * *

 

Gulls cry as they drift over the secluded beach, their calls mixing with the sounds of waves breaking over the surf. The sun beats down on water and sand, heat rising off the white beach and casting liquid mirages down the long stretch.

A flurry of motion comes from the old dock, a brunet man pounding new nails into the weathered wood sticking up along the pathway. Grunting, Kíli hammers another nail into place, sitting back on his haunches and glaring down the dock. “This is ridiculous, I need to scrap this piece of junk and just build a new dock!”

A splashing from below brings a smile to the brunet’s face, setting the hammer aside and leaning over the dock to peer into the shallow water. “Isn’t that right? Do you agree with daddy?” More splashing and a giggle follow, a dark head popping up from the clear water.

Kíli watches his eighteen-month-old daughter lift her head above the small waves, tilting it to the side and peering up at him with a happy cry. She lifts her little arms up to him, tail not yet strong enough to keep her afloat as she sinks back down with a pout. Flicking her small tail, Nerín tries once again to reach up, the tiny gills on the side of her neck flaring out before pressing closed to keep moisture in.

Kíli laughs softly at her antics, swinging his legs over the dock and jumping down into the water next to his daughter. Crouching down, he presses a quick kiss to her head and reaches over to unlatch the makeshift floating playpen Bofur had created. With a happy squeal Nerín swims out and into her father’s arms, little limbs coming up to wrap around his neck. _“Tuni!”_

“Did you have a good nap?” Kíli murmurs, one hand shifting the dark hair back from her face as she nods against his chest. Kíli sits in the shallow water, holding his daughter closer and humming happily. Nerín leans back into the embrace, big blue eyes focusing on the dock to their right.

With a sigh, Kíli follows her gaze, grimacing when he remembers he still has half the dock to finish repairing. “Where’s your Da?” He asks the girl, a garbled string of mer language spilling from Nerín’s lips in reply. Kíli groans and lies back suddenly, bringing the giggling mermaid down with him into the water. Feeling Nerín’s small hands clench over his shoulders, Kíli sits up, pushing his mop of wet hair back from his face.

“I can’t understand your secret language, Little Miss.” Kíli laughs, a grin stealing over his face as he leans in to rub his nose against Nerín’s.

“Largashalmbla smallishionsg rubbadafferatty,” Kíli garbles back to the mermaid, Nerín erupting into peals of laughter as her father tries to speak in the musical tone. Kíli continues to butcher the beautiful language, both of them freezing when they hear a splash sound out to their right. Wide eyes turn toward the noise, Nerín crying out happily and wiggling in Kíli’s arms.

“What you doing?” Fíli asks with a raised brow, eyes narrowed on Kíli’s guilty face as he swims toward the two. Kíli sets Nerín down when Fíli gets closer, the brunette mermaid zooming happily into Fíli’s arms with a squeal. The blond gives Kíli another suspicious look before he ducks down under the waves to greet his daughter.

Kíli lies back, knowing Nerín is recounting everything they’ve been doing since she’s awakened, though it hasn't been much. Kíli’s heart clenches as his daughter speaks to Fili, though he brushes it aside and thinks about the bubbling laughter Nerín so often emits.

Nerín picked up the merfolk language almost instantly, though she still hasn't spoken a single word Kíli can understand. She’s called him ‘ _Tuni’_ as long as she’s been speaking at all, much to Fíli’s enjoyment and Thorin and Dwalin’s shock. Kíli smiles to himself as he remembers the first time she said it, Thorin looking completely shocked while he himself remained completely clueless to what it meant.

 _“Father, provider, safe,”_ Fíli had whispered in his ear, Kíli looking down at the tiny being he and Fíli had made, Nerín’s sunny smile and completely pure love warming his entire body. The proud smile hadn’t left his face for days.

Shaking his head, Kíli tunes back into the present, watching Fíli’s golden hair floating just below the surface. Nerín can understand him, but can’t seem to form the words Kíli longs to hear. Fíli told him she would speak when she’s ready, so the brunet pushes away the slight pang and focuses on the fluffy clouds above them.

“It’s not fair you can understand her,” Kíli pouts to the sky, oblivious to his daughter’s approach.

Giving her tail a hard flick, Nerín launches herself from the water onto Kíli’s stomach, her father making an exaggerated huffing noise and sinking below the shallow water. Nerín’s small hands are at his shoulders in seconds, pulling and urging him back to the surface. Leaning in she nuzzles her face against Kíli’s neck and latches onto his dark hair.

_“Tuni!”_

“She understand you, Kee.” Fíli points out, moving to sit next to the brunet in the sand. He watches them with a smile, Kíli making faces at Nerín and giggling along with the baby. Fíli whistles sharply, Nerín freezing and turning to look at him.

Fíli begins to speak to her softly but Nerín turns away, surprising Fíli and making Kíli laugh as she continues their game and tries her best to make a face. Fíli says something else, but Nerín remains focused on her human father.

“Nerín, are you ignoring Da?” Kíli laughs, wrapping his hands around her tiny waist and lifting her above the water. Nerín squeals happily, slapping her tail in the water when Kíli drops her back down. He repeats this game, much to Fíli’s amusement.

“Too much like you, Kee” Fíli mutters, reaching out and tickling Nerín’s stomach, the tiny mermaid shrieking happily as she twists in Kíli’s hold.

“Da is just jealous, isn’t he, Ner?” Kíli coos as he leans back into the water. “Tuni loves you so much, Little Miss.”

Nerín’s face scrunches up as she lies on Kíli’s chest, her mouth opening and closing as she squirms around restlessly. Kíli raises his brow, turning to look at Fíli when her face starts turning red. “Nerín? What’s wrong?”

Fíli whistles again but Nerín whines when he tries to put her back under the water. Her little hands slide over Kíli’s skin, tail slapping the water as she tries to make the right noises.

“Fíli? What’s she—”

“Kee!” Nerín finally gurgles, turning wide eyes to Kíli as if to gauge his reaction. When he gapes wordlessly she frowns, repeating the word and slapping her tail for emphasis. “Kee!”

“Did she just…” Kíli trails off, a wide smile spreading across his face as Nerín giggles happily. “Nerín, say my name again!”

“ _Tuni_!”

“No, what does Da call Tuni?”

“Kee!” Nerín babbles around a few other sounds, but the endearment Fíli uses is there and spoken perfectly by his daughter. Kíli shouts happily, lifting Nerín high into the air and blowing raspberries on her stomach. The mermaid squeals in excitement, repeating her new word as if it’s the only thing she can say now. “Kee, Kee, _Tuni_ , Kee!”

“Oh Nerín, you were just making Tuni wait, weren’t you? Being ornery just like your Da!”

Fíli snorts and leans against the brunet human, slapping Kíli’s chest before reaching over and taking their daughter into his arms. He ducks under the water with her and a few bubbles surface, Kíli smiling as wide as the day Nerín was born.

When they return both mers look out towards the end of the dock, Thorin surfacing with a smile when Nerín wiggles around in Fíli’s arms. Fíli lets her go with a laugh, Nerín swimming toward her grandfather a bit unevenly. Thorin ducks under the water to greet her, Fíli leaning over to press a kiss to the stubble of Kíli’s cheek. “She did it, Fíli,” Kíli whispers giddily, looking fondly at Fíli’s uncle and their daughter who surface a few feet away.

“Kee?” Thorin grins with a raised brow, sending Nerín into another round of giggles and repeating the word. She swims back to her parents and nudges up into Fíli’s lap, tugging on the lock of hair with Kíli’s bead.

“Kee,” Nerín coos and reaches for Kíli’s hand, settling contently in Fíli’s lap and playing with her father’s fingers. Thorin speaks to Fíli in low rumbles, the brunet human completely enthralled with Nerín and her tiny hands tangling in his own. He leans down to press a kiss to dark hair, the mermaid reaching up and trapping his head with hands on his cheeks.

Puckering his lips Kíli blows a raspberry, crossing his eyes and sending Nerín into a fit of giggles. She slaps her wet hands against Kíli’s face and nearly falls backwards, Fíli pressing a steady hand to her back as he continues his conversation with Thorin.

 _“Tuni!”_ Nerín reaches for Kíli, Fíli passing her over and the little one settling in his lap, reaching up to pat at his stubble lined cheeks again. A few minutes later he and Nerín are rolling around in the water, a mess of splashes and giggles. Thorin disappears and Fíli turns to his family, whistling and gaining both of their attention.

“Nerín hungry?” He grins when his daughter swims over, tugging at the flat fins of his tail excitedly. She’s babbling in her strange mix of mer, baby talk and now English. Kíli wades over with an excited grin, pressing a kiss to Fíli’s cheek and whispering in his ear.

“Let’s get the blanket and take her to Mama.”

Fíli turns and looks into Kíli’s eyes for a few seconds before nodding, scooping Nerín up and handing her off to Kíli. “Wait here.” He smiles at them before ducking under, Kíli lifting Nerín up into the air with a laugh.

“Ready to go see Grandma, Ner?”

* * *

 

 

**Notes for the Chapter:**

> Hahaaa cliffhanger? Now you know what the next chapter will be about!


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